He was the son of a cafe owner from Saint-Nazaire, a lawyer and later a journalist and co-founder with Jaurès of the French Socialist Party (1901). He quickly became known for his gifts of oratory and his strong personality. He entered Parliament in 1902 and was the recorder of the famous law of separation of Church and State of 1905, which he applied as Minister of Public Education and Religions in the Sarrien and Clemenceau governments (1906-1909). He had an extraordinary career, and was named minister 23 times (17 times as minister of Foreign Affairs) and 11 times President of the Council.

He initiated the Salonika expedition and the Balkan front during the First World War. In 1921, he presided over international settlements following the war and from 1925 acquired an international audience at the League of Nations, multiplying his opportunities to work for peace: the pact of Locarno of the 16th of October 1925, a meeting with Stresemann in Thoiry in 1926, renunciation of the occupation of the Rhineland five years before the scheduled end and the Briand-Kellog pact signed in August 1928. In September 1929, well before Jean Monnet, he launched the idea of the United States of Europe and a European Federal Union. Aristide Briand was defeated by Paul Doumer in the presidential election of 1931. He retired in 1932 and died in the same year.